/**
    * 浏览器检测
*/
(function() {
    function browserVersion() {
        var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串  
        var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1; //判断是否IE<11浏览器  
        var isEdge = userAgent.indexOf("Edge") > -1 && !isIE; //判断是否IE的Edge浏览器  
        var isIE11 = userAgent.indexOf('Trident') > -1 && userAgent.indexOf("rv:11.0") > -1;
        if(isIE) {
            var reIE = new RegExp("MSIE (\\d+\\.\\d+);");
            reIE.test(userAgent);
            var fIEVersion = parseFloat(RegExp["$1"]);
            if(fIEVersion == 7) {
                return 7;
            } else if(fIEVersion == 8) {
                return 8;
            } else if(fIEVersion == 9) {
                return 9;
            } else if(fIEVersion == 10) {
                return 10;
            } else {
                return 6;//IE版本<=7
            }   
        } else if(isEdge) {
            return 'edge';//edge
        } else if(isIE11) {
            return 11; //IE11  
        }else{
            return -1;//不是ie浏览器
        }
    }
    var versions = browserVersion();
    // alert(versions)
    if (versions == 6 || versions == 7 || versions == 8 || versions == 9 || versions == 10){
        alert(versions)
    }
    
})()
